Field of the Invention
This invention relates generally to an eye treatment system, and more specifically to an eye treatment system with an advanced fluidics pump interface.
Description of the Related Art
Volumetric pumps such as peristaltic pumps are used to remove fluid and other material from a surgical site. For example, in ophthalmic surgical systems, volumetric pumps may be used to precisely regulate the flow of fluid from the eye during a cataract, vitrectomy, or other surgical procedure. Because of the sterile environment necessitated by these procedures, portions of the pump and other components of the fluidic system, such as valves and sensors, may be configured within a disposable and/or separable fluidics cassette that is replaced or separately sterilized after a surgery.
In the case of a peristaltic pump, several fingers or rollers are circularly disposed within a pump head that rotates such that the fingers successively engage a tubing portion through which a fluid is pumped. As the fingers engage the tubing portion, fluid within a volume of the tubing is entrapped between successive pairs of rollers and so transferred from an inlet of the pump to an outlet.
One problem encountered with peristaltic and other volumetric pumps is that as each finger of the pump initially engages the tubing portion, compression of the tubing portion produces a localized pressure variation that is subsequently transmitted upstream to a surgical handpiece and into the eye as a pressure wave. If the pressure fluctuation is too large or sudden, damage to the eye may result.
Various approaches to dealing with unwanted pressure fluctuations produced by peristaltic and other types of volumetric pumps have been proposed, including those disclosed in U.S. Pat. Nos. 5,230,614 and 6,962,488, which are herein incorporated by reference. While these solutions may work in some surgical systems, other systems place more demanding challenges to the mitigation of pressure fluctuation. Such demands include tight cassette packaging constraints, the use of multiple pumps in a single cassette, or orientation of the pump within the cassette.
Because of the increasing demands produced by advances surgical and other fluidics systems, there is a need for more advanced solutions in mitigating the occurrence of pressure fluctuations produced by volumetric pumps.